An ultrasonic diagnostic apparatus which takes an image of a test object has conventionally displayed a structure of a living tissue of the test object, for example, in B-mode image. In recent years, the patent document 1, for instance, discloses an ultrasonic diagnostic apparatus that displays an elastic image that shows hardness and softness of the living tissue of the test object. As a method to generate the elastic image, the patent document 1 discloses that time-series images of the living tissue when a pressure is applied onto a diagnostic part are obtained, and correlates thus obtained time-series images to calculate a displacement and distortion of the living tissue, as well as measuring or estimating the pressure on the test object on the contact surface. According to the displacement and the pressure being calculated, elastic modulus of each of points on a tomographic image is obtained by an arithmetic computation, and the elastic modulus on each of the points configures an elastic image which shows a distribution of those points. Element data items of the elastic image being configured (elasticity data) are provided with hue information or monochrome brightness information according to a value of the elastic modulus, and these data items are displayed on a screen. With the configuration above, according to the hue of each part, it is possible to display an elastic image in which the elastic modulus level on each part can be identified.
Non-patent document 1 discloses that a mean value and a standard deviation of the elastic modulus are previously obtained, as to (a) lipid and (b) mixed composition of smooth muscle and collagen fiber, and then, points on the elastic image obtained in the ultrasonic diagnostic apparatus are classified into (a) lipid area, (b) mixed area of the smooth muscle and the collagen fiber, and (c) other tissue area. Then, each area is colored and displayed.
[Patent Document 1]
Japanese Published Unexamined Patent Application No. Hei05-317313
[Non-Patent Document 1]
Clinical Pathology 2003; 51: 8: 805-812